Z-filter media with reverse-flow cleaning systems and methods

ABSTRACT

A method for cleaning a filter having Z-media includes providing a filter having Z-media and cleaning the media construction by directing a pulse of compressed gas into the media construction through the downstream flow face. Filter elements useable with such methods include elements made of Z-media. An example system utilizing the method includes a gas turbine air intake system.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/432,923, filed on Dec. 11, 2002, which application is hereinincorporated by reference.

This application is related to a U.S. utility patent applicationentitled REVERSE-FLOW CLEANING SYSTEMS AND METHODS, having AttorneyDocket No. 758.1631US01, which application is being filed concurrentlyherewith and incorporated herein by reference.

TECHNICAL FIELD

This disclosure relates to Z-filter media, filter elements, systems, andmethods. In particular, this disclosure relates to Z-filter media,filter elements, systems, and methods with reverse-flow cleaning, suchas pulse cleaning. In certain examples described, this disclosurerelates to filtering of gas useful with gas turbine systems.

BACKGROUND

Filters are used to purify a variety of fluids, including gas andliquid. The filter media used for the purification, over time, will loadwith contaminant. Filters are used until they are plugged (contaminantblocks all flow through the media) or until a predetermined restrictionlevel is reached. Both are associated with flow and the work necessaryto move the flow. Either too little fluid is allowed to flow through, ortoo much work is required to move the desired flow due to the higherrestriction.

In some systems, pulse jet cleaning is used to periodically removecontaminant from the upstream side of the filter media. Usingpulse-cleaning increases the life of the filter by decreasing therestriction and increasing the service interval. Pulse-cleaning has beenused with pleated filters in arrangements described in U.S. Pat. Nos.4,364,751; 4,218,227; 4,331,459; and 5,575,826, each of which isincorporated by reference herein.

SUMMARY OF THE DISCLOSURE

A method for cleaning a filter having Z-media is provided. The methodincludes providing a filter having Z-media and cleaning the mediaconstruction by directing a flow of pressurized fluid into the mediaconstruction through the downstream flow face.

Filter elements useable with such methods are described.

An example system utilizing the method is described, with respect to agas turbine air intake system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of one embodiment of a portion of a gasintake system for a gas turbine system having filter arrangements andutilizing methods in accordance with principles disclosed herein;

FIG. 2 is a schematic, front elevational view of the gas intake systemshown in FIG. 1, with only portions of the system being shown;

FIG. 3 is a perspective view of a portion of the gas air intake systemrepresented in the schematic view of FIGS. 1 and 2;

FIG. 4 is a perspective view of a pair of filter elements useable in thegas intake system depicted in FIGS. 1-3;

FIG. 5 is a schematic, cross-sectional view of the gas intake system,the cross-section being taken along the line 5-5 of the schematic viewof FIG. 2;

FIG. 6 is an exploded, perspective view of one of the filter elementsdepicted in FIG. 4;

FIG. 7 is an enlarged view of a portion of the cross-section depicted inFIG. 5;

FIG. 8 is a top plan view of an end cap of one of the filter elementsdepicted in FIG. 4;

FIG. 9 is a top plan view of another end cap of the other of the filterelements depicted in FIG. 4;

FIG. 10 is a schematic, perspective view showing a portion of the filterelement useable with the system for securing the filter element onto theframe of the gas intake system;

FIG. 11 is a schematic view showing gas flow with the arrangement ofFIG. 10;

FIG. 12 is a perspective, schematic view showing a portion of filtermedia useable with the filter elements depicted in FIGS. 1-11;

FIG. 13 is a perspective, schematic view of the filter media of FIG. 12arranged in a stacked configuration that is useable for the filterelements depicted in FIGS. 1-11;

FIG. 14 is a perspective view of a portion of the filter elementdepicted in FIGS. 4 and 9; and

FIG. 15 is a diagram showing one example embodiment of a layout of themedia packs with respect to directions of gas flow.

DETAILED DESCRIPTION A. FIGS. 1 and 2, System of Use

The methods of use, gas cleaner arrangements, and constructionsdisclosed herein are useable with a variety of systems. FIGS. 1 and 2depict one example system. In this case, the example system shown is agas turbine system. The gas turbine system is shown in FIG. 1schematically at 20.

In FIG. 1, gas, such as air, is shown drawn into an air intake system 22at arrows 23. The air intake system 22 includes a plurality of gasfilter arrangements 24 generally held in a tube sheet 36.

The air is cleaned in the gas filter arrangements 24, and then it flowsdownstream at arrows 26 into gas turbine generator 28, where it is usedto generate power.

It should be understood that in FIG. 2, only a portion of the air intakesystem 22 is depicted. This is for purposes of clarity and explanation.

B. Overview of Gas Filter Arrangement, System, and Method

FIG. 3 depicts a schematic, perspective, partially exploded view of aportion of the air intake system 22 of FIGS. 1 and 2. Depicted in FIG. 3is a frame 30 that is used to support the tube sheet 36 and the gasfilter arrangements 24. In reviewing FIGS. 1-3, it can be appreciatedthat the frame 30 can be constructed in accordance with desired designcriteria. The frame 30 typically will include a number of cross membersand supporting beams and other structural components.

Still in reference to FIG. 3, the frame 30 supports the tube sheet 36.The tube sheet 36 defines a plurality of apertures or through holes 38.Mounted in the tube sheets 36 and in air flow communication with theapertures 38 are a plurality of gas filter arrangements 24.

In the embodiment shown, each of the gas filter arrangements 24 includesat least one filter element 40 positioned to purify gas before it isused by downstream components, such as the generator 28. Certainpreferred gas filter arrangements 24 configured in example arrangementsare described in further detail below.

In general, air to be purified flows from the atmosphere and through thefilter element 40. The filter element 40 is positioned in air flowcommunication with the tube sheet 36. The purified gas will flow throughthe aperture 38 and then into systems for use, such as the generator 28.

After a period of use, the pressure drop across the filter element 40will increase due to the collection of impurities in the gas stream. Thefilter elements 40 are periodically cleaned by directing a flow of ahigher pressure fluid (such as a pulse of compressed gas) into thefilter element 40 in a direction from the downstream side of the filterelement to the upstream side of the filter element 40. This will removeat least some of the contaminant and particulate matter from the filterelement 40 and reduce the restriction across the filter element 40.

C. Example Gas Filter Arrangement

FIG. 4 illustrates one example embodiment of gas filter arrangement 24useable with reverse-flow cleaning methods as described herein. The gasfilter arrangement 24 includes at least one filter element 40. Thefilter element 40 includes at least a first filter media construction 42made from a flexible, permeable material. The filter media constructionincludes Z-filter media 44. The term “Z-filter media” is meant to referto filter media in which individual ones of corrugated, folded, orotherwise formed filter flutes are used to define sets of inlet andoutlet filter flutes for fluid flow through the media. Some examples ofZ-filter media are provided in U.S. Pat. Nos. 5,820,646; 5,772,883;5,902,364; 5,792,247; 5,895,574; 6,210,469; 6,190,432; 6,350,296;6,179,890; 6,235,195; Des. 399,944; Des. 428,128; Des. 396,098; Des.398,046; and Des. 437,401; the complete disclosures of each of thesepatents are incorporated by reference herein.

One particular type of Z-filter media utilizes two media componentsjoined together to form the media construction. The two components are aflexible corrugated sheet and a flexible non-corrugated sheet. Thecorrugated media and non-corrugated sheet together are used to definethe inlet and the outlet flutes. In some instances, the corrugated sheetand the non-corrugated sheet are secured together and then coiled toform a Z-filter media construction. Such an arrangement is described,for example, in U.S. Pat. Nos. 6,235,195 and 6,179,890, both of whichare incorporated herein by reference. In certain other arrangements,some non-coiled sections of corrugated media secured to flat media arestacked on one another to create a filter construction. An example ofthis type of construction is described in FIG. 11 of U.S. Pat. No.5,820,646, and in U.S. Pat. No. 5,772,883, each of which is incorporatedherein by reference. In general, filter element configurations utilizingZ-filter media are sometimes referred to as “straight through flowconfigurations” or by variants thereof. In general, in this context,what is meant is that the filter elements generally have an inlet flowface and an opposite exit flow face, with flow entering and exiting thefilter cartridge in generally the same straight through direction.

In FIG. 12, there is a depiction of the Z-media 44 in perspective view.In FIG. 12, the Z-media 44 is a two-layered construction 45, formed froma flexible flat (non-corrugated) sheet 46 secured to a flexiblecorrugated sheet 47. In general, on one side 48 of the corrugated sheet47, a first set of flutes 49 is formed; and, on an opposite second side50, a second side of flutes 51 is formed. In FIG. 12, edge 53 wouldcorrespond to an inlet edge; and edge 54 would correspond to an outletedge. In this context, Z-media 44 refers to media made from a flexible,permeable material. One example includes cellulose. This is in contrastto constructions made from ceramics used in, for example, exhaustsystems.

The cellulose media can be treated with fine fiber, for example fibershaving a size (diameter) of 5 microns or less, and in some instances,submicron. Useable fine fiber is described in commonly assigned U.S.patent application Ser. No. 09/871,583, filed May 31, 2001 incorporatedby reference herein. A variety of methods can be utilized to apply thefine fiber to the media. Some such approaches are characterized in, forexample, U.S. Pat. No. 5,423,829, column 32, lines 48-60, incorporatedby reference herein. Further, methods are described in U.S. Pat. Nos.3,878,014; 3,676,242; 3,841,953; and 3,849,241, each being incorporatedherein by reference.

In general, the corrugated sheet 47 that is shown in the drawings is ofa type generally characterized herein as having a regular, curved, wavepattern of corrugations. The term “wave pattern” in this context ismeant to refer to a corrugated pattern of alternating troughs and ridgesthat repeat. The term “regular” in this context is meant to refer to thefact that (1) the troughs and ridges repeat with generally the samerepeating corrugation shape and size; and (2) each trough is an inverseof each ridge. That is, the term “regular” is meant to indicate that thecorrugation pattern comprises equal troughs and ridges and that eachpair (an adjacent trough and ridge) repeats, without substantialmodification in size and shape of the corrugations. The term“substantial” in this context, when referenced to the modification,refers to a modification resulting from a change in the corrugationprocess or form used to create the corrugation sheet, as opposed tominor variations from the fact that the material of the sheet 47 isflexible. With respect to the characterization of repeating pattern, itis not meant that in any given filter construction, there must be anequal number of ridges and troughs present. Rather, the media could beterminated, for example, between a pair comprising a ridge and a trough,or partially along a pair comprising a ridge and a trough.

In this context, the term “curved”, when used with the term “regular,curved, wave pattern of corrugations”, it is meant to refer to acorrugation pattern that is not the result of a folded or creased shapeprovided to the media. Rather, the apex of each ridge and the bottom ofeach trough is formed along a radiused curve. A typical radius for suchmedia would be within the range of 0.5-10 mm.

The first set of flutes 49 is closed. In the example shown, the firstset of flutes is closed with sealant adjacent the edge 54 by a sealantbead 56, or similar structure. Similarly, the second set of flutes 51 isclosed. In the example shown, the second set of filters 51 is sealedadjacent to the first edge 53 by a sealant bead 57. In preferredembodiments, the sealant beads 56, 57 is either flush with (even with)its respective edge 54, 53 or even protrudes beyond the its respectiveedge 54, 53. Preferably, for advantageous operation of the reverse-flowcleaning system, the sealant beads 56, 57 will not be recessed or spacedfrom its respective edge 54, 53.

In other arrangements, the flutes may be closed at their ends usingcrushing, darting, or other types of deformations. An example of flutedmedia having deformed ends is described in commonly assigned U.S.provisional patent application 60/395009 filed Jul. 10, 2002 and PCTapplication US03/02799 filed Jan. 31, 2003, both of which areincorporated by reference herein. In addition, the flutes could betapered, as described in FIG. 1 of WO 97/40918 and PCT WO 03/47722, bothof which are incorporated by reference herein. Tapered flutes would be acurved wave pattern, but would not be a “regular” pattern, as that termis used herein. While the example embodiment shows the use of a sealantto close the flutes, other techniques can be used. For example, theflutes can be closed with urethane. In addition, the flutes can beclosed by using ultrasonics.

The sheet of corrugated media 47 secured to the flat sheet 46 can thenbe arranged in a variety of fashions to form a filter element 40. Oneexample is coiling the flat sheet 46 and corrugated sheet 47. An exampleof a coiled filter element formed in this way is shown in U.S. Pat. Nos.5,820,646 and 5,895,574, incorporated herein by reference. In theparticular embodiment shown in FIG. 12, the flat sheet 46 secured to thecorrugated sheet 47 is stacked to form a stacked or layered construction60. The stacked construction 60 includes a plurality of pieces of twolayered constructions 45 secured to corrugated sheet 47 stacked adjacentto each other and secured together. In the embodiment shown in FIG. 12,there are 5 pieces of two layered constructions 45.

From a review of FIG. 12, it should be apparent how the Z-media 44functions. In general, the first set of flutes 49 are open at inlet edge53, and thus comprise inlet flutes 49. Each of the inlet flutes 49 areclosed at edge 54, (their exit ends) as a result of sealant bead 57 orsimilar closure at this location. Thus, gas that enters flute 49 atinlet edge 53 must pass through the media 44 (either the corrugatedsheet 47 or the flat sheet 46) to escape from the inlet flutes 49. Uponpassage through the media, filtering occurs, and fluid flow enters asecond set of flutes 51 (outlet flutes), at a location downstream fromthe bead 56. Outlet flutes 51 are open along edge 54; thus, the filteredgas stream can flow out of the media 44. This type of construction isgenerally characterized herein as Z-filter media.

In FIG. 13 is another view of the Z-media 44 arranged in the stackedconstruction 60. Each of the two layered constructions 45 is secured toits next adjacent sheet. In the example illustrated, the layeredconstructions 45 are secured together by way of one of the sealant beads56 or 57. In the example shown in FIG. 13, the bead 56 is shown. In FIG.13, the edges of the flutes 51 can be seen. As will be described furtherbelow, in preferred arrangements, the stacked construction 60 is securedto and sealed within an end cap, which provides a gas-tight closure tothe side 62 of the stacked construction 60.

Attention is again directed to FIG. 4. In preferred embodiments, thefilter element 40 will include a pair of media constructions 42,depicted as a first media construction 64 and a second mediaconstruction 66. In the arrangement shown, each of the first and secondmedia constructions 64, 66 is constructed from Z-media 44. In thespecific example embodiment shown, the first and second mediaconstructions 64, 66 are stacked constructions 60 of Z-media 44.

Each of the first and second media constructions 64, 66 has inlet flutes49 forming an upstream flow face 68 and outlet flutes 51 formingdownstream flow face 70. FIG. 4 depicts the Z-media constructions 64, 66schematically. As such, only small sections 44 a of the media is shown.It should be understood that the entire upstream face 68 and downstreamface 70 are constructed of Z-media 44.

Attention is directed to FIGS. 12, 13, and 15. In the preferredembodiment, each of the layered constructions 45 is secured to itsadjacent layered construction 45 spaced not flush with the ends, butoffset, to create a slanted block 400 of flutes 51. FIG. 12 shows eachlayered construction 45 spaced unevenly with its next adjacent layeredconstruction 45, with the layered construction 45 on the top of theslanted block 400 being the one most projecting from the page, while thebottom layered construction 45 is the one most recessed into the page.FIG. 13 shows layered construction 45 a relative to layered construction45 b. Layered construction 45 b is recessed away from layeredconstruction 45 a. Layered construction 45 c is recessed relative tolayered construction 45 b. This pattern is continued. The result of thispattern is the slanted block 400. If each layered construction 45 wereeven with its next adjacent layered construction 45, each of the fluteends would be flush and even with each other. In the particular exampleshown, each layered construction 45 is parallel to all other layeredconstructions 45.

In the example illustrated, each layered construction 45 is oriented atan angle relative to a vertical axis 402 (FIG. 15). Axis 402 is thecenterline that bisects the V-configuration 72. Axis 402 is also theline that is generally orthogonal to the tube sheet 36. The angle ofeach layered construction 45 relative to the axis 402 is shown at 404 inFIG. 15. The angle 404 is at least 10°, less than 90°, and preferably40°-50°.

Still in reference to FIG. 15, the slanted block 400 results in lessturbulence because of a smaller angle that the air flow must pass.Reference numeral 406 illustrates the angle that the air flow must turnthrough the slanted block 400. This angle 406 will depend upon theangles 404 of the layered constructions 45 relative to the center line402 as well as the angle 408. The angle 408 is the angle of thedownstream flow face 409 relative to the center line 402. Preferably,the angle 408 is equal to or less than the angle of the flutes 406. Inthe embodiment shown, the angle 408 is 45° or less, preferably 20° orless, and typically 3°-7°. In the embodiment shown, angle 406 is lessthan 80°, typically 30°-70°, and in the one shown is 40°. The air flowturns the angle 406 to pass through the media and then turns anotherangle to pass through the clean air side through the tube sheet. Thisangle that the air flow turns again is roughly the same as angle 406, inthis instance, less than 80°, preferably 30°-70°, and for example about40°. When pulsing, the air pulses flow the same angles, only in anopposite direction. Thus, the pulse jets first flow parallel to thecenter line 402, then turn at angle 406 to pass through the media. Thus,the pulse jets turn at an angle of less than 80°, typically 30°-70°, andfor example 40°.

Still in reference to FIG. 15, it can be seen how in the preferredembodiment, the slanted block includes upstream flow face 410,downstream flow face 409, and end surfaces 411, 412. In the embodimentshown, the slanted block 400 forms a parallelogram and isnon-rectangular. Specifically, end surfaces 411 and 412 are parallel toeach other, while upstream surface 410 is parallel to downstream surface409. However, the angle between the end surfaces 411, 412 are not at 90°relative to the upstream flow face 410 and downstream flow face 409.

Still in reference to FIG. 15, an example embodiment with dimensions isillustrated. In FIG. 15, the distance between the center line 402 andthe down stream face 409 of the media pack nearest the vertex is shownat 416. This dimension, in the example shown, is less than 10 in.,preferably less than 5 in., and typically 2 in.-3 in. The overall lengthof the downstream flow faces 409 as projected onto the center line 402is shown at dimension 418. This length 418 is less than 100 in., greaterthan 10 in., and typically 40 in.-50 in. The length of the downstreamflow face 409 of the media pack 424 nearest the tube sheet as projectedonto the center line 402 is shown at dimension 420. Dimension 420 isless than 70 in., greater than 5 in., and typically 15 in.-30 in. Thedistance between the center line 402 and the downstream flow face 409that is immediately adjacent to the tube sheet is shown at dimension422. Dimension 422 is less than 25 in., greater than 1 in., andtypically 3 in.-10 in.

In reference now to FIG. 7, in the example configuration shown, thefirst media construction 64 and the second media construction 66 arearranged relative to each other such that the downstream flow face 70 ofthe first media construction 64 is directed towards or is facing thedownstream face 70 of the second media construction 66. This can be seenin FIG. 7. In preferred embodiments, the first media construction 64 andthe second media construction 66 are angled relative to each other toform a V-configuration 72. The V-configuration includes an apex 74 and amouth 76. In the particular embodiment shown, the apex 74 does not cometo a precise point between the first and second media constructions 64,66. Rather, it is the region where the first and second mediaconstructions 64, 66 are most closely positioned relative to each other.The mouth 76 is the region where the first and second mediaconstructions 64, 66 are spaced furthest apart from each other.

Still in reference to FIG. 4, in preferred embodiments, the filterelement 40 includes an end panel arrangement 160. The end panelarrangement 160 functions to help support the media construction 42 andto resist forces from loads of pressure (either vacuum or pulsing). Theend panel arrangement 160 also helps to support and hold a gasket,described in further detail below. As embodied herein, the end panelarrangement 160 includes an end panel 161, 162, 163, and 164 on thefirst and second media constructions 64, 66, respectively. Inparticular, the first media construction 64 includes end panel 161, 162,while the second media construction includes end panel 163, 164. It canbe seen that these end panels 161, 162, 163, 164 are located at the endpoints of the media constructions 42. In the illustrated embodiment,these end panels 161, 162, 163, 164 are attached to and sealed againstthe ends of the media construction 42 and provide protection to themedia construction 42.

In preferred embodiments, the filter element 40 will also include an endcap arrangement 80. The end cap arrangement 80 will function to securesides 62, 63 (FIG. 6) of the first and second media constructions 64,66. That is, the end cap arrangement 80 helps to prevent gas flow frombypassing the filter element 40 and proceeding directly into a clean airplenum 82. While a variety of configurations are useful, in the exampleembodiment shown, the end cap arrangement 80 includes a first end cap 84and a second end cap 86. The first and second end caps 84, 86 also helpto secure together the first media construction 64 and the second mediaconstruction 66.

In particular, the first end cap 84 is secured to the side 62 of both ofthe first media construction 64 and the second media construction 66.The second end cap 86 is secured to both of the sides 63 of the firstmedia construction 64 and second media construction 66. The end caps 84,86 secure the media constructions 64, 66 together and help them to holdtheir V-configuration 72. Together with an end construction 90, thefirst and second end caps 84, 86 define the clean air plenum 82. In theillustrated embodiment, the end caps 84, 86 can be secured to the mediaconstructions 64, 66 with adhesive, polyurethane, or other suitablematerials. Preferably, the end panels 161, 162, 163, 164 are firstsecured to the first and second media constructions 64, 66 followed bysecuring the end caps 84, 86.

In certain preferred systems, the gas filter arrangement 40 will includetwo filter elements 40, depicted as element 92 and element 94. Elements92 and 94 are configured to mate together to form an overall V-pack 96(FIG. 7) having a mouth 97 and an apex 98. Element 92, in theconfiguration shown, will typically be the element nearest the tubesheet 36 and sealed with a gasket 105 (FIG. 5) against the aperture 38forming a seal 106. The apex 74 of the element 92 will be in sealingengagement with the mouth 76 of the element 94. In this manner, it canbe appreciated that the general width of the element 92 is greater thanthe width of the element 94. This can be seen in FIG. 7. In thepreferred configuration shown, the elements 92, 94 are mounted onto theframe 30 and sealed together in a way such that they nest with eachother. As mentioned above, the mouth 76 of the element 94 is received byand nests with the apex 74 of the element 92. Typically, a gasket 102(FIG. 5) is used to form a seal 104 between the filter element pair 92,94. The gasket 102 is held by the end panels 161, 162, 163, 164 and theend caps 84, 86.

As can be understood, in assembly of the V-pack 96, the first and secondend caps for each of the elements 92, 94 are generally similar inconstruction. That is, the first end cap 84 of element 92 is similar tothe second end cap 86 of element 92; and likewise for the first andsecond end caps of element 94. However, because of the nested featuresand the differing widths of the elements 92, 94, the first end cap ofelement 92 is different than the first end cap of element 94; andlikewise for the second end caps of elements 92, 94. FIG. 8 illustratesan embodiment of the end caps (more specifically referenced as 284, 286)of element 94; and FIG. 9 illustrates an embodiment of the end caps(more specifically referenced as 384, 386) for element 92. Each of theend caps for each element 92, 94 have some similar constructions whichwill be denoted hereinafter with the same reference numbers for purposesof clarity.

Specific, example embodiments of assembly of the element 92, 94 are nowdiscussed. It should be understood that a variety of ways of assemblingelements 92, 94 are contemplated. The illustrated ones are examples ofmany possibilities. As shown, each of the end caps has a central region202, and first and second tray regions 204, 206. In the illustratedembodiment, the central region 202 generally has a trapezoid shape thatdefines the shape of the clean air plenum 82 of the V-pack 96. Thecentral region 202 can be constructed with a curved section 224. Thecurved section 224 is concave in relation to the clean air plenum 82when assembled (see FIG. 6 for example). The curved section providesstructural stability similar to stability provided by columnar supports,for example, that support compressive forces during gasket loading orassembly. In addition, the curved structure aids in resisting pressureloads experienced during operation of the system. The center region inthe illustrated embodiment includes ribs 226 that extend between innerwalls 216, 218. The ribs provide additional structure stability to theend caps 284, 286, 384, 386.

Still referring to FIGS. 8 and 9, the end caps 284, 286, 384, 386,include first and second recesses 228, 230 located adjacent to ends ofthe tray regions 204, 206. The first recesses 228 are configured tointerconnect with end panels 162, 164; the second recesses areconfigured to interconnect with end panels 161, 163. By providing therecesses 228, 230, the end panels 161-164 are supported by the end caps.In addition, each of the recesses 228, 230 assists in properly locatingthe end panels 161-164 in relation to the media constructions 64, 66 andthe end caps.

Referring now to FIG. 14, one representative end panel (i.e. 164) isshown interconnected to the first recess 228 of an end cap. In FIG. 14,the end panel 164 is illustrated from a view represented by arrow 248 inFIG. 9. Although only one representative end panel is hereinafterdescribed, the principles disclosed apply to the other end panels andend caps.

Typically, the recess 228 is sized and configured to correspond to theshape of the end panel 164. The end panel 164 includes a rib 232 thatfits within the recess 228 such that an upper surface 234 of the rib 232is flush with a planar tray surface 222 of the tray region 206. The rib232 in essence interlocks with the recess 228 for structural stability.

In addition, adhesive or urethane also assists in securely positioningthe end panel 164 in relation to the end cap. Openings or slots 236 areformed in the rib 232 of the end panel 164. Holes 262 are also formedadjacent to the rib 232. The openings 236 and holes 262 permit adhesiveor urethane contained within the tray region 206 to flow through theopenings or holes 236, 262, into the recess 228, and around the rib 232.Typically, the holes 262 are located such that the top of the holes 262are at a level generally equal to the surface level of the adhesive orurethane, which is pour into the tray region 204, 206.

The first and second tray regions 204, 206 of the end caps (284, 286,384, 386) extend along sides 208, 210 of the end caps from a first end242 of the end cap to a second end 244 of the end cap. The tray regions204, 206 generally have a parallelogram shape and extend along the sides208, 210 at an angle. The angle defines the V-shaped of the V-pack 96when assembled to the first media construction 64 and a second mediaconstruction 66. An outer wall 212 (also shown in FIG. 6) extends alonga majority of the perimeter 214 of the end cap. The outer wall 212, incombination with the inner walls 216, 218, define the tray regions 204,206. The construction of the walls 212, 216, 218 provides structuralstability to the end caps.

During assembly, the media constructions 64, 66 are positioned withinthe tray regions 204, 206. The walls 212, 216, 218 assist in properplacement and orientation of the media constructions 64, 66. Further themedia constructions 64, 66 can be adhered to the first and second endcaps. The walls 212, 216, 218 also function to contain an adhesive orurethane within the tray regions 204, 206 for adhesion of the mediaconstructions 64, 66 to the end caps. The tray regions 204, 206 mayinclude a plurality of holes 220 formed in a planar surface 222 of thetray region 204, 206. Overage of adhesive or urethane may flow throughthe holes 220 when the media constructions are assembled to the endcaps.

Once the adhesive or urethane has cured, overage which has cured in theholes 220 functions as mechanical fasteners. The cured overage assistsin fastening the media construction 64, 66 to the end caps in additionto the adhesive bond between the planar tray surface 222 and the mediaconstructions 64, 66. That is, the cured overage bonds to the mediaconstruction and acts as an interconnection within the holes 220 of thetray region. The interconnection does not extend or project from anysurfaces of the tray regions 204, 206. Rather, the cured overage resideswithin the holes 220 formed in the planar tray surfaces 222, whichprovides advantages in stacked filter arrangements. In someapplications, it is desirable to provide holes or openings of differentshapes, or position the holes or openings in an alternative arrangementto accommodate different structural loads.

Referring back to FIG. 14, the end panels (e.g. 164) each include sidegrooves 252. The side grooves are sized and constructed to interconnectto the media constructions 64, 66. In the illustrated embodiment, thegrooves 252 are columnar shaped to provide structural stability underoperational and installation loads. The side grooves include ribs 254that define a pocket 256 for containing an amount of adhesive orurethane used to adhere the media construction to the end panel. Withoutthe ribs 254, the adhesive or urethane would flow to the bottom of theside groove 252 and not be evenly applied to the media construction.

A non-ribbed groove 258 extends along the side grooves 252. Thenon-ribbed groove is also configured to receive adhesive or urethane.Holes 260 (one shown) are formed in the groove 258. Overage of adhesiveor urethane may flow through the holes 260 when the media constructionsare assembled to the end panels. Similar to the interconnects previouslydiscussed with regards to the holes 220 in the tray regions 204, 206,the holes 260 of the end panels 161-164 act as interconnections. Thatis, once the adhesive or urethane has cured, overage that has cured inthe holes 260 functions as a mechanical fastener.

Referring again to FIGS. 8 and 9, the outer wall 212 of the end capsalso defines a first planar gasket sealing surface 238 located adjacentto the first end 242 of the end cap 284, 286 and a second planar gasketsealing surface 240 located adjacent to the second end 244 of the endcap 384, 386 (see also FIG. 5). For element 92, the first planar gasketsealing surface 238 of the end cap 384, 386 is configured to provide asealing surface for the gasket 105 between the element 92 and theaperture 38 of the tube sheet 36 (FIG. 7). The second planar gasketsealing surface 240 of element 92 is configured to provide a sealingsurface for the gasket 102 that is located between the elements 92, 94.Similarly, for element 94, the first planar gasket sealing surface 238of the end cap 284, 286 is configured to provide a sealing surface forthe gasket 102 between the elements 92, 94. The second planar gasketsealing surface 240 of element 94 is configured to provide a sealingsurface between element 94 and the end construction 90. As can beunderstood, the end panels 161-164 also include sealing surface, showngenerally at 250 in FIG. 4, that continue the sealing surface providedby the first and second gasket sealing surfaces of the end caps for eachof the gaskets or other sealing components.

D. Mounting Arrangements

The filter elements 40 are useable, in the example shown, with the airintake system 22 of a gas turbine system 20. The elements 40 aremountable onto the frame 30, using a variety of mechanisms. One examplemounting system is shown in FIGS. 3 and 7-11.

In FIG. 3, a mounting system in the form of a yoke is shown at 110. Theyoke 110 has a series of supports that generally are in the shape of theclean air plenum 82. As such, the yoke 110 also has the shape of aV-configuration 112. Each of the yokes 110 extends from one of theapertures 38 in the tube sheet 36. Each of the elements 40 is mountedover the yoke 110 by sliding over the yoke 110 through the mouth 76. Inthe configuration shown in FIG. 3, the filter element 92 is mountedfirst over the yoke 110, such that it extends through the mouth 76, andout of the apex 74 of the element 92 and through the mouth 76 of theelement 94.

Referring back to FIG. 14, yoke guides 246 are positioned adjacent tothe first end 242 of the end cap. The yoke guides 246 are located ateach of the inner walls 216, 218 (only one shown in FIG. 14). The yokeguides 246 are configured to guide and properly align the filterarrangement 24 on the yoke 110 (FIG. 3) during installation. Inparticular, the yoke guides 246 guide the yoke 110 to position andsupport the filter arrangement 24 at surface structures 247. The surfacestructures 247 are formed at opposite ends of the panel 164 adjacent tothe grooves 252 (only one surface structure 247 shown).

Referring now to FIGS. 3-4 and 10-11, further details of the mountingsystem are shown. In FIG. 10, a connection system 116 that securestogether the apex 98 of the V-pack 96 is shown. The system 116 includesthe end construction 90 that closes the apex 98 and forms an end of theclean air plenum 82. In the illustrated embodiment, the system 116includes a bolt 124 (FIG. 3) that extends from a portion of the yoke110.

Referring to FIG. 10, the end construction 90 preferably has anon-porous contoured end piece 134. The end piece 134 includescontoured, rounded surface 136. The end piece 134 defines an aperture138, through which the bolt 124 extends. The bolt 124 receives asuitable mating fastener, such as a nut 140. Upon tightening of the nut140, the end piece 134 is compressed against the filter arrangement 24and forms a seal 106 with the tube sheet 36. This also squeezes thefilter element 92 and 94 between and against the end piece 134 to form aseal 129 (FIG. 5). FIG. 11 shows the flow of gas as it encounters thegas filter arrangement 24 including the end piece 134.

E. Reverse-Flow Cleaning System

Attention is directed to FIGS. 3, 5, and 7, from which a more detailedunderstanding of the reverse-flow cleaning system 150 will beunderstood. In general, the reverse-flow cleaning system 150 uses a flowof a higher pressure fluid, such as pulses of gas, such as air, to cleanthe V-packs 96. By “pulse”, it is meant a flow of fluid at a pressure atleast 10%, typically at least 25% higher than the flow at the inlet end,and for a limited time duration. Typically time durations are under 10seconds, typically under 5 seconds and in some cases, less than 0.5seconds.

In reference now to FIGS. 3 and 7, the pulse jet cleaning system 150includes a plurality of pulse jet valves 152, each valve having anassociated nozzle 154. A compressed air manifold 156 can be seen in gasflow communication with the valves 152, which directs gas through blowpipes 155 and to nozzles 154. In FIG. 5, it can be seen how the nozzles154 are spaced a distance from the tube sheet 36. This distance is atleast 8 inches, no greater than 36 inches, and typically 20-28 inches.

In general, the reverse pulse system 150 can be operated using an aircompressor. Periodically, the valves 152 can be operated to allow apulse jet of compressed gas to pass through the nozzles 154, through theapertures 38 in the tube sheet 36, and into the clean air plenum 82 ofthe V-pack 96. In general, the pulse jet of air is directed in a reversedirection, backwards, or as a back flush through the V-packs 96. By theterm “in a reverse direction,” it is meant that the pulse jet of air isdirected opposite to normal gas flow, i.e., filtering air flow (duringfiltering of ambient air). Such a direction of gas flow will tend toflush dust or other particles collected on the V-packs 96 therefrom. Thepulse jet system 150 may, in general, except for the geometricconfigurations described and shown herein be similar to the arrangementsdescribed in U.S. Pat. Nos. 4,331,459; 4,364,751; and 5,575,826,incorporated herein by reference. In some preferred systems, the pulsejet system will use systems as described in commonly assigned andco-pending application Ser. No. ______, filed the same date as thisapplication, entitled “Reverse Flow Cleaning Systems and Methods” andcarrying attorney docket number 758.1631US01, incorporated herein byreference.

In general, it has been found that for certain particular applications,it will be beneficial to direct the pulse of compressed gas at a forceof between 5-55 inches of water. This is measured at the downstream facewith a face measured permeability value of 65-70.

F. Methods of Operation and Service

In general, a method using systems and configurations described hereinwill comprise providing a filter having a Z-media configuration 44. Thefilter with the Z-media configuration 44 can be cleaned by directing aflow of pressurized fluid into the media construction 42 through thedownstream flow face. This will cause dust or other particulate matterto be moved away from the upstream flow face.

The step of directing a flow of pressurized fluid may include directinga pulse of compressed gas. Directing a pulse of compressed gas caninclude periodically directing the pulse of compressed gas into themedia construction through the downstream flow face. By “periodic”, itis meant that the reverse-flow cleaning system 150 can be programmed orcan be manually operated such that in desired periods, after a certainlength of time or after a certain amount of restriction is detected,there will be a pulse of compressed gas directed through the downstreamflow face. In the configurations shown, one useful range is directingthe compressed gas at a force of 5-55 inches of water.

When arranged in the configurations shown, it is useful to direct thepulse of compressed gas into the clean air plenum 82 of the V-pack 96.

The air intake system 22 can be used to clean ambient air before it isused by the gas turbine generator 28 (FIG. 1). In use, ambient air willbe directed into the gas filter arrangements 24. The air will enter theupstream flow faces 68, pass through the Z-media 44, and exit throughthe downstream flow faces 70 into the clean air plenum 82. The cleanedair will then flow through the apertures 38 in the tube sheet 36 andthen be directed into the generator 28. After a period of use or afterreaching some initial restriction, the pulse jet cleaning system 150will direct a pulse of compressed gas or air through the apertures 38,into the clean air plenum 82, through the downstream flow face 70,through the Z-media 44, and out through the upstream flow face 68. Thiswill knock loose dust or other particulate matter from the Z-media 44.The pulse of gas will turn at angle 406 (FIG. 15) to enter the flow face70 (shown as 409 in FIG. 15). As discussed above, the angle 406 is lessthan 80°, typically 30°-70°, for example 40°.

After some period of use, it will be advantageous to service the airintake system 22. Servicing will include removing the filter elements 40and replacing them with new filter elements 40. To service the airintake system 22, the connection system 116 is manipulated todisassemble the gas filter arrangements 24. The nut 140 is removed fromthe bolt 124. This breaks the seal 129 between the end piece 134 and theelement 94 of the V-pack 96. This also releases the seal 104 between theelements 92, 94. This also releases the seal 106 between the element 92and the tube sheet 36. The elements 92, 94 are slid off of the yoke 110.They are then recycled or disposed of.

New filter elements 92, 94 are then supplied. New filter element 92 isfirst slid over the yoke 110 until the end is against the tube sheet 36.New element 94 is supplied and is slid over the yoke 110 until its mouth76 is engaged against the apex 74 of element 92. The end construction 90is then put into place. This is done by placing the end piece 134 intothe apex 98 and then tightening the nut 140 onto the bolt 124. This willcreate the seal 106 between the tube sheet 36 and the element 92; theseal 104 between elements 92 and 94; and the seal 129 between the endpiece 134 and the element 94. The gas filter arrangement 24 is thenagain useable.

1-20. (canceled)
 21. A gas filter system comprising: (a) a frame havinga tube sheet defining an aperture; (b) a first filter element mounted onthe frame and sealed against the tube sheet in gas-flow communicationwith the aperture; the first filter element including: (i) at least afirst media construction; the first media construction having oppositefirst and second ends and a plurality of flutes; (ii) each of the fluteshaving a first end portion adjacent to the first media constructionfirst end, and a second end portion adjacent to the first mediaconstruction second end; (A) selected ones of the flutes being open atthe first end portion and closed at the second end portion; and selectedones of the flutes being closed at the first end portion and open at thesecond end portion to result in an upstream flow face and a downstreamflow face; and (c) a cleaning system oriented to send flow ofpressurized fluid into the first media construction through thedownstream flow face, and out of the first media construction throughthe upstream flow face.
 22. A system according to claim 21 wherein: (a)the first media construction includes: (i) a plurality of stacked mediamembers; each of the media members having a corrugated sheet secured toa flat sheet.
 23. A system according to claim 22 wherein: (a) thecorrugated sheet comprises a regular curved wave pattern ofcorrugations.
 24. A system according to claim 21 wherein: (a) thecleaning system includes at least one pulse jet valve and a compressedair manifold in gas flow communication with the valve.
 25. A systemaccording to claim 21 wherein: (a) the cleaning system includes aplurality of pulse jet valves and a compressed air manifold in gas flowcommunication with the valves.
 26. A system according to claim 25wherein: (a) each of the valves includes a nozzle.
 27. A systemaccording to claim 26 wherein: (a) each nozzle is spaced a distance fromthe tube sheet no greater than 36 inches.
 28. A system according toclaim 26 wherein: (a) each nozzle is spaced a distance from the tubesheet at least 8 inches.
 29. A system according to claim 21 wherein: (a)said first filter element includes the first media construction and asecond media construction; the second media construction having oppositefirst and second ends and a plurality of flutes; (i) each of the secondmedia construction flutes having a first end portion adjacent to thesecond media construction first end, and a second end portion adjacentto the second media construction second end; (A) selected ones of thesecond media construction flutes being open at the second mediaconstruction first end portion and closed at the second mediaconstruction second end portion; and selected ones of the flutes beingclosed at the second media construction first end portion and open atthe second media construction second end portion to result in a secondmedia construction upstream flow face and a second media constructiondownstream flow face; (b) said first media construction and said secondmedia construction being secured together; (i) said first mediaconstruction downstream flow face opposing said second mediaconstruction downstream flow face to form a clean air plenum in gas flowcommunication with the aperture in the tube sheet.
 30. A systemaccording to claim 29 wherein: (a) said first filter element furtherincludes first and second opposite end caps; (i) said first mediaconstruction being secured to and extending between said first andsecond end caps; (ii) said second media construction being secured toand extending between said first and second end caps; and (b) said firstmedia construction and said second media construction are angledrelative to each other to form a V-configuration having an apex and amouth; (i) said mouth being sealed against said tube sheet.
 31. A methodcomprising: (a) providing a media construction; the media constructionbeing made from a flexible, permeable material and having opposite firstand second ends and a plurality of flutes; (i) each of the flutes havinga first end portion adjacent to the media construction first end, and asecond end portion adjacent to the media construction second end; (A)selected ones of the flutes being open at the first end portion andclosed at the second end portion; and selected ones of the flutes beingclosed at the first end portion and open at the second end portion toresult in an upstream flow face and a downstream flow face; (b) cleaningthe media construction by directing a pulse of compressed gas at aforce/area of 5-55 inches of water into the media construction throughthe downstream flow face.
 32. A method according to claim 31 wherein:(a) said step of cleaning includes removing at least some particulatematerial from the plurality of flutes by forcing the particulatematerial out of the flutes through the upstream flow face.
 33. A methodaccording to claim 31 wherein: (a) said step of cleaning includescausing dust or other particulate matter to be moved away from theupstream flow face.
 34. A method according to claim 31 wherein: (a) saidstep of directing a pulse of compressed gas includes periodicallydirecting the pulse of compressed gas.
 35. A method according to claim31 wherein: (a) said step of providing a media construction includesproviding a first filter element having a first media construction and asecond media construction; the first media construction and the secondmedia construction each having Z-media; (i) the first media constructionand second media construction being arranged in a V-shape to define aclean air plenum therebetween.